To make the green shimmer shot, place the melon liqueur, coconut rum, and green shimmer dust in a shaker. (Do not use ice for the shots.)
Shake or stir the mixture and distribute between four shot glasses.
To make the pink shimmer shot, place watermelon liqueur, coconut rum, and pink shimmer dust in a shaker. (Do not use ice for the shots.)
Shake or stir the mixture and distribute between four shot glasses.
Work in batches to make the mango pisco sour (unless you have an extra-large shaker). Place the pisco, mango juice, lime juice, and egg whites in a shaker filled with ice.
Vigorously shake and divide the cocktail between rocks glasses.
Garnish the glasses with pineapple leaves, lime slices, and grapefruit slices.
Serve with the shimmer shots on the side for DIY floaters.